Multi-frequency output light source device, exposure equipment and photoetching equipment

Abstract

The utility model provides a multi-frequency output light source device, exposure equipment and photoetching equipment. The device comprises a laser light source, a splitter, a plurality of nonlinear optical crystals and a plurality of optical filters, the splitter is provided with a plurality of output light paths, and each output light path is sequentially provided with a nonlinear optical crystal and an optical filter; the laser light source is used for outputting a first laser signal with the frequency within a preset frequency range; the splitter is used for splitting the first laser signal into a plurality of second laser signals, and the second laser signals are in one-to-one correspondence with the output light paths; the nonlinear optical crystals are used for performing frequency conversion on the second laser signals to obtain third laser signals, and the nonlinear optical crystals correspond to the third laser signals with different frequencies; the optical filter is used for filtering the third laser signal to obtain a fourth laser signal, and the wavelength of the fourth laser signal is located in different preset wavelength ranges. The device is simple in structure, the research and development and use cost is reduced, and maintenance is convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor manufacturing, and particularly relates to a multi-frequency output light source device, an exposure device and a lithography device. Background Art

[0002] The multi-frequency laser combined light source mainly includes a control circuit, a power supply module, and laser light sources such as red light, green light, far-infrared light (FIR), and near-infrared light (NIR), so as to output lasers with different wavelengths.

[0003] The multi-frequency laser combined light source can be applied to various devices. For example, in an exposure device, it is used as an alignment light source, and four single-frequency laser light sources work together for alignment. However, the existing combined light source integrates multiple light sources into one body, which is not convenient for detecting and replacing damaged parts. Therefore, when one of the four laser light sources appears abnormal, the entire combined light source will become unavailable. In addition, the structure of the multi-frequency laser light source is complex, and the R & D and usage costs are relatively high. Summary of the Utility Model

[0004] The present utility model is proposed in view of the above problems. The present utility model provides a multi-frequency output light source device, an exposure device and a lithography device, which have a simple structure, reduce the R & D and usage costs, and are convenient for maintenance.

[0005] In a first aspect of the present utility model, a multi-frequency output light source device is provided. The multi-frequency output light source device includes a laser light source, a splitter, a plurality of nonlinear optical crystals, and a plurality of optical filters. The splitter has a plurality of output optical paths, and the nonlinear optical crystals and the optical filters are sequentially arranged on each output optical path;

[0006] The laser light source is configured to output a first laser signal with a frequency within a preset frequency range;

[0007] The splitter is connected to the laser light source and is configured to split the first laser signal into a plurality of second laser signals, and each of the second laser signals corresponds to one of the output optical paths;

[0008] The nonlinear optical crystal is configured to perform frequency conversion on the second laser signal to obtain a third laser signal, wherein each of the nonlinear optical crystals corresponds to a third laser signal with a different frequency;

[0009] The optical filter is configured to filter the third laser signal to obtain a fourth laser signal, and the wavelengths of the fourth laser signals output by each optical filter are respectively within different preset wavelength ranges.

[0010] In one embodiment of the present utility model, a plurality of the nonlinear optical crystals and / or a plurality of the optical filters are provided in the output optical path.

[0011] In one embodiment of the present utility model, the nonlinear optical crystal is selected from one or more of a frequency doubling crystal, a sum frequency crystal, a difference frequency crystal, an optical parametric amplification crystal, and an optical parametric oscillation crystal.

[0012] In one embodiment of the present utility model, when the nonlinear optical crystal is a frequency doubling crystal, the frequency doubling crystals in each of the output optical paths have different frequency doublings.

[0013] In one embodiment of the present utility model, the frequency doubling crystal is selected from any one of potassium titanyl phosphate crystal, β-phase barium metaborate crystal, and lithium triborate crystal.

[0014] In one embodiment of the present utility model, the multi-frequency output light source device is an alignment light source, and the alignment light source includes four of the nonlinear optical crystals and four of the optical filters.

[0015] In one embodiment of the present utility model, the four optical filters are respectively used for outputting red light, green light, far-infrared light, and near-infrared light.

[0016] In one embodiment of the present utility model, the optical splitter can be selected from a planar waveguide optical splitter or a traveling wave optical splitter.

[0017] In one embodiment of the present utility model, the optical filter can be selected from any one of a fiber grating filter, an arrayed waveguide grating filter, an M-Z interference filter, and an acousto-optic tunable filter.

[0018] In a second aspect of the present utility model, there is provided an exposure apparatus, which includes the multi-frequency output light source device, an alignment device, and an exposure device according to any one of the above first aspects;

[0019] The multi-frequency output light source device is configured to output optical signals of multiple different wavelengths;

[0020] The alignment device is configured to align a mask and a device to be exposed;

[0021] The exposure device is configured to project a pattern on the mask onto the device to be exposed, and perform an exposure process on the device to be exposed to obtain an exposed device; wherein, the multi-frequency output light source device serves as an alignment light source and / or an exposure light source of the exposure device.

[0022] In a third aspect of the present utility model, there is provided a lithography apparatus, including: an exposure device and a developing device;

[0023] The exposure device includes the multi-frequency output light source device described in any one of the above first aspects, and the exposure device is configured to image a mask pattern onto a wafer coated with a photoresist.

[0024] The developing device is configured to apply a developer to the surface of the wafer for development.

[0025] The multi-frequency output light source device according to an embodiment of the present invention includes a laser light source, a splitter, at least two nonlinear optical crystals, and at least two optical filters arranged in sequence. Frequency modulation is performed by the nonlinear optical crystals to obtain light sources of multiple wavelengths, so that the structure of the light source device is simple, the research and development and use costs of multi-frequency light sources are reduced, and it is convenient for maintenance. Description of the Drawings

[0026] By describing the embodiments of the present invention in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present invention will become more obvious. The drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation to the present invention. In the drawings, the same reference numerals generally represent the same components or steps.

[0027] Figure 1 is a schematic structural diagram of a multi-frequency output light source device according to an embodiment of the present invention;

[0028] Figure 2 is a schematic structural diagram of a multi-frequency output light source device according to another embodiment of the present invention. Detailed Embodiments

[0029] In order to make the objectives, technical solutions, and advantages of the present invention more obvious, exemplary embodiments according to the present invention will be described in detail below with reference to the drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments of the present invention. It should be understood that the present invention is not limited by the exemplary embodiments described herein. Based on the embodiments of the present invention described herein, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] First, refer to Figure 1 to describe the multi-frequency output light source device according to an embodiment of the present invention. The multi-frequency output light source device of the present invention can be applied to exposure equipment, lithography equipment, and of course, other equipment, such as medical equipment. The present application does not limit the application scenarios of the multi-frequency output light source device.

[0031] As Figure 1As shown in the figure, the present application proposes a multi-frequency output light source device 100. The multi-frequency output light source device 100 includes a laser light source 110, a splitter 120, a plurality of nonlinear optical crystals 130, and a plurality of optical filters 140 arranged in sequence. The splitter 120 has multiple output optical paths, and a nonlinear optical crystal 130 and an optical filter 140 are sequentially arranged on each output optical path. In the figure, N≥2, and N is a positive integer.

[0032] The laser light source 110 is used to output a first laser signal with a frequency within a preset frequency range.

[0033] The splitter 120 is connected to the laser light source 110 and is used to split the first laser signal into a plurality of second laser signals, and each second laser signal corresponds to each output optical path one by one.

[0034] The nonlinear optical crystal 130 is used to perform frequency conversion on the second laser signal to obtain a third laser signal, where each nonlinear optical crystal corresponds to a third laser signal with a different frequency.

[0035] The optical filter 140 is used to filter the third laser signal to obtain a fourth laser signal, and the wavelengths of the fourth laser signals output by each optical filter 140 are respectively located in different preset wavelength ranges.

[0036] In the present application, the nonlinear optical crystal 130 includes, but is not limited to, one or more of a frequency doubling crystal, a sum-frequency crystal, a difference-frequency crystal, an optical parametric amplification crystal, and an optical parametric oscillation crystal.

[0037] The frequency doubling crystal may include one or more of a second harmonic generation crystal and a third harmonic generation crystal, etc. Among them, the second harmonic generation crystal has the function of second harmonic generation (SHG), and the third harmonic generation crystal has the function of third harmonic generation (THG). For example, the second harmonic generation crystal can achieve the function of doubling the frequency and halving the wavelength, and the third harmonic generation crystal can achieve the function of increasing the frequency by 2 times and the wavelength being one-third of the original wavelength.

[0038] The sum-frequency crystal has the function of sum-frequency generation (SFG). The difference-frequency crystal has the function of difference-frequency generation (DFG). The input of the sum-frequency crystal can be two or more laser beams, and the output is a laser beam with a frequency that is the sum of the frequencies of the two or more laser beams. The input of the difference-frequency crystal can be two or more laser beams, and the output is a laser beam with a frequency that is the difference between the frequencies of the two or more laser beams.

[0039] When the nonlinear optical crystal is a sum - frequency crystal or a difference - frequency crystal, the sum - frequency crystal and the difference - frequency crystal are arranged on at least two output optical paths of the splitter 120. When the nonlinear optical crystal is a frequency - doubling crystal, an optical parametric amplification crystal or an optical parametric oscillation crystal, the frequency - doubling crystal is arranged on one output optical path of the splitter 120, so as to realize the frequency conversion of the input laser signal.

[0040] Since the characteristics of the nonlinear optical crystal are determined by the material and there is no complex design, when performing frequency conversion through the nonlinear optical crystal, the power supply device can quickly replace the nonlinear optical crystal to meet the wavelength requirements of different frequencies, and can quickly use the mature nonlinear optical crystal materials, which is convenient for the upgrade and update of the multi - frequency light source device.

[0041] The multi - frequency output light source device of the embodiment of the present utility model can adjust the frequency of a single - frequency laser light source through the nonlinear optical crystal and filter through the optical filter, so as to realize multi - frequency output based on a single light source. Since a single - frequency laser light source replaces multiple different - frequency laser light sources, the dependence on multiple types of frequency lasers is reduced, and the device structure is simple, reducing the R & D and usage costs. Moreover, when an abnormality occurs, more precise processing technical effects can be carried out according to the problem, increasing the maintainability of the light source.

[0042] In some embodiments of the present application, the laser light source includes a laser and a laser controller, and the laser controller is electrically connected to the laser.

[0043] The laser light source is composed of a laser and a laser controller. The laser is a semiconductor laser that can output a single discrete wavelength, and the laser controller is used to control the switch of the laser and control the emission of the laser by controlling the switch.

[0044] Exemplarily, the laser is a gas laser, or a solid - state laser, or a semiconductor laser, or a fiber laser.

[0045] In some embodiments of the present application, multiple nonlinear optical crystals and / or multiple optical filters are arranged on the output optical path. Through multiple nonlinear optical crystals, a single - frequency laser light source can be adjusted in multiple frequencies, and through filtering by the optical filter, the output range of the frequency can be further expanded.

[0046] In some embodiments of the present application, when the nonlinear optical crystal is a frequency - doubling crystal, the frequency - doubling crystals located in each output optical path have different frequency - doubling factors. The frequency - doubling crystal can be used to frequency - convert the laser wavelength, thereby expanding the tunable range of the laser.

[0047] Specifically, the frequency doubling crystal is selected from any one of potassium titanyl phosphate (KTiOPO4, KTP) crystal, β-barium metaborate (BBO) crystal, and lithium triborate (LBO) crystal. Among them, nonlinear optical crystals located in different output optical paths use frequency doubling crystals of different materials, so that third laser signals of different frequencies can be obtained.

[0048] The BBO crystal has a very high damage threshold and nonlinear coefficient, and a wide transparent range (189 - 3500 nm), and is suitable for nonlinear optical applications such as frequency doubling, third harmonic generation, and parametric oscillation in a wide wavelength band.

[0049] The KTP crystal has good nonlinear optical performance in the near-infrared band, high frequency doubling efficiency, and high damage threshold.

[0050] The LBO crystal has an extremely high damage threshold, a relatively high nonlinear optical coefficient, and a wide transparent range (160 - 2600 nm). It is suitable not only for frequency doubling and third harmonic generation, but also for optical parametric oscillation and frequency mixing.

[0051] In some embodiments of the present application, the optical splitter can be selected as a planar waveguide optical splitter or a traveling wave optical splitter.

[0052] The planar waveguide optical splitter uses two parallel optical fiber plates as waveguides, and adjusts the coupling effect of the waveguides by controlling the distance between the waveguides, so as to distribute the input optical signal to different output ports.

[0053] The traveling wave optical splitter uses a single optical fiber to distribute the optical signal to different output ports according to different reflection principles.

[0054] In some embodiments of the present application, the optical filter can be selected from any one of a fiber grating filter, an arrayed waveguide grating filter, an M-Z interference filter, and an acousto-optic tunable filter. At least two optical filters are of different types, or at least two optical filters are of the same type.

[0055] Next, refer to Figure 2 to describe the multi-frequency output light source device according to the embodiment of the present invention. The multi-frequency output light source device of this embodiment is used in an exposure device and serves as an alignment light source. Figure 2 The direction indicated by the arrow in is the transmission direction of the laser.

[0056] As Figure 2 shown, in this embodiment, the multi-frequency output light source device includes a superluminescent light-emitting diode, a planar waveguide type optical splitter (PLC Splitter), four nonlinear optical crystals of different materials, and four grating filtering optical fibers.

[0057] The PLC optical fiber splitter performs splitting based on planar optical waveguide technology. In the PLC optical fiber splitter, the optical waveguide array is located on the upper surface of the chip, and the splitting function is achieved by changing the evanescent field coupling (coupling degree and coupling length) between the optical fibers and changing the core radius of the optical fibers to obtain different splitting amounts.

[0058] The superluminescent diode is connected to the input end of the nonlinear optical crystal. Each nonlinear optical crystal is used to perform frequency conversion on the laser, so that the four nonlinear optical crystals made of different materials can respectively output optical signals with wavelengths of λ1, λ2, λ3, and λ4. In the embodiment of the present application, the laser generated by the superluminescent diode can polarize the atoms in the nonlinear optical crystal, that is, the separation of positive and negative charge centers. This separation is a dynamic vibration with a frequency consistent with that of the laser. For second-order frequency doubling, the polarization intensity is proportional to the square of the laser electric field intensity. Therefore, the second-order nonlinearity will generate a frequency-doubled polarization vibration, and the frequency-doubled vibration will generate frequency-doubled light, thus realizing the frequency and wavelength conversion of light.

[0059] The four grating-filtered optical fibers respectively filter the optical signals of λ1, λ2, λ3, and λ4. Here, the grating filtering is based on the grating diffraction principle. By using gratings with different parameters, specific frequency light can be allowed to pass through, and other frequency light is diffracted to other directions or eliminated, thereby realizing filtering.

[0060] After filtering, the four grating-filtered optical fibers can output red light, green light, far-infrared light, and near-infrared light.

[0061] Specifically, the green light is laser light within the wavelength range of 492 nanometers (nm) to 577 nanometers, the red light is laser light within the wavelength range of 625 nanometers to 740 nanometers, the near-infrared light is laser light within the wavelength range of 780 nanometers to 1100 nanometers, and the far-infrared light is laser light within the wavelength range of 8 micrometers (μm) to 14 micrometers.

[0062] In this embodiment, the low-frequency light generated by the superluminescent diode is split into different lines by the PLC optical fiber splitter, and then nonlinear optical crystals with different frequency doublings are added to the lines. The characteristics of the crystals are used to change the passing laser, forming light with different frequencies. Finally, the wavelengths belonging to the preset range are filtered by the filtered optical fibers, and finally multiple single-frequency lights are obtained. Thus, a single light source can achieve multi-frequency output.

[0063] In this embodiment, the technology of frequency modulation of a laser by a nonlinear optical crystal is integrated with the alignment light source of an exposure device. The technologies of PLC optical fiber splitting and grating filtering are used to ensure the stability of the light source, changing the long-term situation where exposure devices have long required various types of laser alignment light sources. It realizes a reduction in the demand of exposure devices for different types of laser light sources, enables the same light source to meet the demand for multiple wavelength light sources in actual use, and optimizes the problem that it is inconvenient to detect and replace damaged parts when multiple light sources are integrated into one body, improving the maintainability of the alignment module of the exposure device.

[0064] An embodiment of the present application also provides an exposure device, which includes a multi-frequency output light source device, an alignment device, and an exposure device as described in any of the above embodiments;

[0065] The multi-frequency output light source device is used to output optical signals of multiple different wavelengths;

[0066] The alignment device is used to align the mask and the device to be exposed;

[0067] The exposure device is used to project the pattern on the mask onto the device to be exposed and perform an exposure process on the device to be exposed to obtain an exposed device; wherein, the multi-frequency output light source device serves as the alignment light source and / or the exposure light source of the exposure device.

[0068] An embodiment of the present application also provides a lithography device, including: an exposure device and a developing device;

[0069] The exposure device includes a multi-frequency output light source device as described in any of the above embodiments, and the exposure device is used to image the mask pattern onto the wafer coated with photoresist;

[0070] The developing device is used to apply a developer to the surface of the wafer for development.

[0071] Specifically, the multi-frequency output light source device can be used in the alignment system of the exposure device of the lithography device.

[0072] Since the multi-frequency output light source device uses the frequency conversion technology of a nonlinear optical crystal, it can adjust the frequency of a single-frequency laser light source, thereby realizing the replacement of multiple different-frequency laser light sources with a single-frequency laser light source, reducing the dependence on various types of frequency lasers, and using the separate design idea for different frequency paths, which can be processed more precisely according to the problem when an abnormality occurs, and can well replace the original light source working mode when the alignment system of the lithography machine needs to perform alignment operations.

[0073] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present utility model thereto. Those of ordinary skill in the art can make various changes and modifications therein without departing from the scope and spirit of the present utility model. All such changes and modifications are intended to be included within the scope of the present utility model as claimed in the appended claims.

[0074] In the specification provided herein, a large number of specific details are set forth. However, it can be understood that the embodiments of the present utility model can be practiced without these specific details. In some instances, well-known methods, structures, and technologies have not been shown in detail so as not to obscure the understanding of this specification.

[0075] Similarly, it should be understood that, in order to streamline the present utility model and assist in understanding one or more of the various utility model aspects, in the description of the exemplary embodiments of the present utility model, the various features of the present utility model are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present utility model should not be construed as reflecting an intention that the claimed present utility model requires more features than those expressly recited in each claim. Rather, as reflected by the corresponding claims, the novelty of the utility model lies in that the corresponding technical problems can be solved with fewer features than all the features of a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into the detailed description, where each claim itself serves as a separate embodiment of the present utility model.

[0076] Those skilled in the art can understand that, except for features that are mutually exclusive, any combination can be adopted for all the features disclosed in this specification (including the accompanying claims, abstract, and drawings) and for all the processes or units of any method or device so disclosed. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) can be replaced by an alternative feature that provides the same, equivalent, or similar purpose.

[0077] In addition, those skilled in the art can understand that, although some of the embodiments described herein include certain features included in other embodiments rather than other features, the combination of the features of different embodiments means that it is within the scope of the present utility model and forms different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0078] It should be noted that the above embodiments are illustrative of the present invention rather than restrictive of the present invention, and those skilled in the art can design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in the claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The present invention can be implemented by means of hardware including several different elements and by means of a suitably programmed computer. In a unit claim listing several devices, several of these devices may be embodied by the same item of hardware. The use of the words first, second, and third, etc. does not denote any order. These words may be interpreted as names.

[0079] As described above, the above is only the specific implementation manner or the description of the specific implementation manner of the present invention, and the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention. The protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A multi-frequency output light source device, characterized in that, The multi-frequency output light source device includes a laser light source, a splitter, a plurality of nonlinear optical crystals, and a plurality of optical filters. The splitter has a plurality of output optical paths, and the nonlinear optical crystal and the optical filter are sequentially arranged on each output optical path; The laser light source is configured to output a first laser signal with a frequency within a preset frequency range; The splitter is connected to the laser light source and is configured to split the first laser signal into a plurality of second laser signals, and each of the second laser signals corresponds to one of the output optical paths; The nonlinear optical crystal is configured to perform frequency conversion on the second laser signal to obtain a third laser signal, wherein each of the nonlinear optical crystals corresponds to a third laser signal with a different frequency; The optical filter is configured to filter the third laser signal to obtain a fourth laser signal, and the wavelengths of the fourth laser signals output by each optical filter are respectively within different preset wavelength ranges.

2. The multi-frequency output light source device according to claim 1, wherein A plurality of the nonlinear optical crystals and / or a plurality of the optical filters are arranged on the output optical path.

3. The multi-frequency output light source device according to claim 1, wherein The nonlinear optical crystal is selected from one or more of a frequency doubling crystal, a sum frequency crystal, a difference frequency crystal, an optical parametric amplification crystal, and an optical parametric oscillation crystal.

4. The multi-frequency output light source device according to claim 3, characterized in that, When the nonlinear optical crystal is a frequency doubling crystal, the frequency doubling crystals located in each of the output optical paths have different frequency doublings.

5. The multi-frequency output light source device according to claim 4, wherein The frequency doubling crystal is selected from any one of potassium titanyl phosphate crystal, β-phase barium metaborate crystal, and lithium triborate crystal.

6. The multi-frequency output light source device according to claim 4, wherein, The multi-frequency output light source device is an alignment light source, and the alignment light source includes four of the nonlinear optical crystals and four of the optical filters.

7. The multi-frequency output light source device according to claim 6, wherein The four optical filters are respectively configured to output red light, green light, far-infrared light, and near-infrared light.

8. The multi-frequency output light source device according to claim 1, wherein, The splitter can be selected as a planar waveguide optical splitter or a traveling-wave optical splitter.

9. The multi-frequency output light source device according to claim 1, wherein, The optical filter can be selected from any one of a fiber grating filter, an arrayed waveguide grating filter, an M-Z interference filter, and an acousto-optic tunable filter.

10. An exposure apparatus, characterized in that, The exposure device includes the multi-frequency output light source device according to any one of claims 1-9, an alignment device, and an exposure device; The multi-frequency output light source device is configured to output a plurality of optical signals with different wavelengths; The alignment device is configured to align a mask and a device to be exposed; The exposure device is configured to project the pattern on the mask onto the device to be exposed, and perform an exposure process on the device to be exposed to obtain an exposed device; wherein the multi-frequency output light source device serves as an alignment light source and / or an exposure light source of the exposure device.

11. A lithographic apparatus, characterized in that, Comprising: An exposure device and a developing device; The exposure device includes the multi-frequency output light source device according to any one of claims 1-9, and the exposure device is configured to image a mask pattern on a wafer coated with a photoresist; The developing device is configured to apply a developer to the surface of the wafer for development.

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